lwrobins

The DHLA 48 on my ported 4 port has a lean miss @ 2200-3200 (approx) under light throttle. The idle circuit is good what's the next progression? Please don't say a modded Nikki.

wankel=awesome

At that point, enough air should be passing through the boosters to pull from the main jet.

Maybe dirt? Verify everything. Pull the mains, maybe even step them up.

Your vac advance not working will make a lean cruise too, btw.

lwrobins

Thanks, The vac advance is not connected. I will also look into the ignition timing.

j9fd3s

iTrader: (3)

the classic problem with the webers is to run the F11 emulsion tube, which is just not applicable to our engines. it causes a lean miss because its too slow to get the main circuit running.

test for it is to pull the whole main stack out, and go drive somewhere without traffic, you will quickly see what the idle circuit does.

test 2, is to put the car in 4th at an rpm below where the idle circuit stops working and floor it. if the main circuit is correct, it'll just go. if the mains aren't coming on,
it'll run on the accelerator pump for a second, and then just completely stop running.

lwrobins

I cant find my timing light, but I've retarded the leading timing a little and here's an old VW trick, not sure if this is a maintenance item on these cars or not. added a few drops light oil to the top of the dizzy shaft to lube the mechanical advance weights. So far so good. Improved.

wankel=awesome

My bet is advance.

on my car, when the advance comes on at 4k RPM the engine goes a full 2 points RICHER on the AFR gauge, not leaner like people would think.

t_g_farrell

iTrader: (1)

I had the same issue with my Dell DHLA 48 at times. Is yours a RB modified one? If not they modified
the AP to give a longer squirt to help with this.

Heres a great page to explain how to start tuning a Dell.

This is a rundown of what I've learned from my own personal experiences with Dellorto carburetors on RX7s

lwrobins

Yes, when I rebuilt it I think I got the last AP spacer racing beat had. and thanks for the page!

lwrobins

Turns out my dell likes less fuel pressure, similar to the webbers. 4-4.5 is too much!

t_g_farrell

iTrader: (1)

Yep, my Dell liked to be at the same pressure as a nikki, 2.5 - 3.5 psi and lower was better in that range.